Combination plastic and paperboard containers are well known as evidenced by U.S. Pat. Nos. 1,938,490; 1,951,249; 3,215,267; 3,480,138; 3,527,346; 3,608,705; 3,746,242; and 3,904,029. The foregoing patents include blister type packages, window display type packages, paperboard packages with plastic inserts or vice versa, and boxes made of plastic and paperboard. While each provides the advantages of certain of the most desirable characteristics of both paperboard and plastic, no one container maximizes such advantages and is also capable of being shipped in a substantially flat configuration and can be setup, filled, and closed by standard packaging machines.
Of course, there are a great number of paperboard containers which can be setup, filled, and closed by standard paperboard folding carton machinery. An example of a paperboard hanging package which can be processed by such machinery is disclosed in U.S. Pat. No. 3,985,232. It is constructed from a single sheet of paperboard. Similar types of all plastic containers made from a single sheet of material are also known. Of course, containers made from more than one sheet of material are also well known and an example of a plastic container made from two sheets of the same material can be found in U.S. Pat. No. 1,992,087.
Blister packages, although unpopular with most customers mainly because they are difficult to open, are in common use today. Packages of this type comprise a molded shell or blister of transparent plastic heat sealed to a generally planar base element, usually of fibrous material, such as paperboard. Identifying indicia or advertising matter are printed on that side of the paperboard to which the blister of plastic is affixed, following which the board is coated with a thermoplastic material to which the blister is heat sealed by means of peripheral flange which extends outwardly from the blister. Advantages of blister packages include visual display of the product which appeals to persons having impulse buying habits, limited protection of the product from deterioration as for example by atmospheric moisture or other causes, pilfer-proof protection, and protection of the product from rough handling both in shipment and by potential customers.
However, blister packages have a number of drawbacks. Molding of the blisters requires the use of very expensive molds, and even the production of a sample blister necessitates the making of a costly wood mold. The blisters and paperboard backings must be shipped separately from the manufacturer to the user, and the latter must have expensive equipment for heat sealing the blister to the paperboard after insertion of the product or products into the cavity of the blister. The coating of synthetic plastic applied over the printed surface of the paperboard tends to lessen the quality and appearance of the printed matter. Although the blister can be printed, this can only be accomplished at great expense and trouble. Another undesirable aspect of the common form of blister package is that it cannot stand up at one end, but either must be suspended, as for example on a punch board, or laid flat. A particularly disadvantageous feature of the common blister package is that the package is very difficult to open and is ordinarily destroyed in the act of being opened, for opening involves delamination or destruction of the paperboard. Thus, if the package contains a plurality of items, (e.g. nuts and bolts), after opening, the entire contents of the package must be removed and those items which are not immediately used must be stored in some type of a container, such as a jar.
Another form of package widely used to display goods is that made entirely from transparent synthetic plastic material. Although such packages can be fabricated from a sheet of transparent plastic and shipped in a flat condition to the user where they are set up and filled, they too have certain disadvantages. Being substantially clear or transparent, it may be necessary to coat portions thereof with an opaque ink, for example a white ink, in order that other indicia or advertising material printed thereon will be legible. Furthermore, printing of plastic sheet is rather expensive. Rigidity of the packages is limited and is not readily increased merely by increasing the thickness of the plastic sheet material, since there are mechanical limitations involved in using thicker sheets, as well as the self-defeating aspect of the increased cost of such plastic sheets.